In recent years, ionic liquids have been extensively evaluated as environmental-friendly or “green” alternatives to conventional organic solvents for a broad range of organic synthetic applications. Ionic liquids offer some unique characteristics that distinguish them from conventional organic solvents, such as no effective vapor pressure, a broad liquid range, high polarity and charge density, can be either hydrophobic or hydrophilic, and unique solvating properties.
One widely studied class of ionic liquids includes imidazolium salts, such as 1-butyl-3-methylimidazolium hexafluorophosphate, also known as [bmim][PF6]. Other well known ionic liquids include 1-ethyl-3-methylimidazolium chloride-aluminium (III) chloride, which is usually referred to as [emim]Cl—AlCl3; and N-butyl pyridinium chloride aluminium (III) chloride, which is usually referred to as [Nbupy]Cl—AlCl3. A broad range of ionic liquids have also been investigated in the following references: U.S. Pat. Nos. 6,048,388; 5,827,602; US 2003/915735A1; US 2004/0007693A1; US 2004/0035293A1; WO 02/26701; WO 03/074494; WO 03/022812; and WO 04/016570.
Published PCT Application WO 2004/003120 discloses ionic liquid based products suitable for use in surface or air treating compositions, and ionic liquid cocktails containing three or more different and charged ionic liquid components. The products are particularly useful in various consumer product applications, such as home care, air care, surface cleaning, laundry and fabric care applications.
It is desirable to take advantage of the various unique characteristics of the ionic liquid to form compact or concentrated products. Specifically, it is desirable to form compositions comprising an ionic liquid active composed of an ion active and an ionic liquid-forming counter ion, wherein the ion active is capable of delivering a fabric treating benefit, a surface treating benefit, and/or an air treating benefit. The composition in its supercompact (i.e., highly concentrated) form is substantially free of added water.
Additionally, it is desirable that such compositions have a low viscosity of less than about 5000 mPa·s at room temperature. It is also desirable that such compositions can be easily diluted with water and/or solvents without formation of a gel phase (i.e., a high viscosity phase) during the dilution process.